Former ER series regular Alex Kingston is joining The CW’s breakout superhero drama Arrow in a recurring guest star role. The British actress will play Dinah Lance — Laurel’s (Katie Cassidy) mom and Detective Quentin’s (Paul Blackthorne) ex-wife. Later this season Dinah will return to Starling City to make amends with her family that she abandoned years earlier following the tragic death of her daughter aboard Oliver Queen’s (Stephen Amell) yacht.